Firmware update to use Nowind with XV-T550 (Based on version V4.3b)
Installation:
- Insert Nowind on MSX and hold down "F"-key while booting.
- Type on host computer:
nwhostapp -f T550NOWIND.ROM
- Move the Nowind to XV-T550 and you are good to go.

Both of these updates only add support for XV-T550 and do not affect usage of these devices on standard MSX computers.

All information provided is gained by testing on unmodified XV-T550. All parts of it may not be complete or accurate. Generally typical MSX2 functionality is expected unless other vice stated.

General info:
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Sony XV-T550 is Japanese MSX2 although you can't see it by looking at it. This is because video output is disabled during boot logo & other init and will only enabled after the Sony's custom titling program is started.

The controller works partly like MSX keyboard, but there is no enough pins connected to make MSX keyboard to work. Please take a look at service manual for details. PSG sound is delivered to controller already amplified. As I don't have the original controller, this part is not documented. Mouse port is compatible with MSX joystick port 1.

Most easy way to boot up this machine as MSX is to connect mouse port pins 1,2 and 9 together. This will cause it to drop to MSX-BASIC. Note how ever that screen output will be 60Hz, but the hardware can handle only 50Hz sync. If you use the patched firmwares, you don't need to do this.

"Font ROM" of this system contains both menu graphics and fonts. They are stored in to custom file system. I've extracted the files, if someone wants to take a look. Program ROM can be downloaded from Hans Otten page.

*) Please note: bit7 is effective only in address #4FFF. To actually enable video output, you have to execute something from ROM. Any routine is fine. It is only important that CPU fetches an !INSTRUCTION! from ROM. When video output is enabled, SRAM can be disabled again without switching off video.

XV-J550 -> Japanese version of XV-T550
XV-J555 -> Dunno, didn't look it yet
XV-J770 -> MSX2 internals, like XV-T550 (this is the one that Tabajara have). Tabajara puts all the information that he could extract from this machine here: http://www.tabalabs.com.br/msx/titulador/
XV-J777 -> Looks like J770 + Card reader

XV-T600 -> Not MSX related. Main processor is a 6502 and VDP is a RICOH VDP.

From Panasonic:

VW-KT300 -> MSX2+ internals. Custom "MSX-Engine" from NEC it doesn't have all pins and seems to have some kind of megarom mapper inside. Custom BIOS with only the stuff that this titler needs to boot. Can boot MSX1 BIOS but no further progress. I am trying to find how the pages from ROM are mapped on each slot-page.

And, add one more video titler to the list, Victor JX-T500. Look at the picture of the main board, it features a V9958. Yes, it is impossible to read but compare with a bigger picture of the IC. I couldn't find better pictures, only more links like this where MSX word appears... In the previous one as well :P I don't know if the other IC is a Z80 but probably.

NYYRIKKI, should the ROM from sony XV-T550 work on a real MSX computers? Right now, I managed to buy a XV-T550 with mouse included, not sure which model because it is not the typical Sony Hit-Bit mouse :)